The killing of British aid worker David Haines "will not lead Britain to shirk our responsibility" to work with allies to take on ISIS, British Prime Minister David Cameron said Sunday.
Instead, he said, "it must strengthen our resolve," reports GHN based on CNN.
Speaking a day after the Islamic terror group posted a video showing Haines' beheading -- the latest in a string of such videos -- Cameron vowed to work with the United States to support its "direct military action." He also emphasized that "this is not about British troops on the ground."
"We have to confront this menace," Cameron said. "Step by step we must drive back, dismantle, and ultimately destroy ISIL and what it stands for." Together with allies, he said, "we will do so in a calm, deliberate way but with an iron determination."
The group, which calls itself the Islamic State, is also known as ISIS and ISIL.
"This organization poses a massive threat to the entire Middle East," Cameron said, making a public statement before an emergency meeting of security and intelligence officials.
He listed five points in the British strategy: to work with the Iraqi government and Kurdish regional governments and help them protect minorities being slaughtered by ISIS; to work at the United Nations "to mobilize the broadest possible support" against ISIS; to contribute to U.S.-led military action; to assist in humanitarian efforts; and to "reinforce our formidable counterterrorist effort here at home."
Some British Muslims have joined ISIS, and the militant who killed Haines and two Americans -- James Foley and Steven Sotloff -- may be British.
The video of Haines' killing looks very similar to those that showed the beheadings of Foley and Sotloff, and the masked militant sounds like the same man.
"It falls to the government and to each and every one of us to drain this poison from our society and to take on this warped ideology that is radicalizing some of our young people," Cameron said.